The covering of landfills is a practice required by regulation in many jurisdictions. For example, it is often required that the daily fill of garbage be covered at the end of the day, or that the landfill be covered when it is not in operation. It is known in the art to lay strips of film, such as degradable polyethylene, in a side-by-side or overlapping arrangement to cover the landfill, and to place an anchoring material (sometimes called ballast) such as dirt on the film to hold it in place. The ground area that requires regular covering in a landfill may be very large, and machines have been developed to apply strips of film to cover such areas.
WO 2012/061918 (Kozak) discloses a tracked, self-propelled machine for laying a film and depositing an anchoring material on it to cover a landfill. A roll of film is suspended by cables from support arms at the back of the machine for unwinding onto the ground surface as the machine moves forward, and anchoring material is released from the back of a box on the machine and is deposited on the laid film. However, since the film roll is suspended by cables, it swings freely when the machine moves over uneven ground, making it difficult to lay the film in a controlled, regular way. Nor can the operator conveniently adjust the height of the film roll during deployment in response to windy conditions or obstacles such as rocks on the ground surface, nor adjust the angle of the roll relative to the ground surface in response to sloping ground.
There remains a need for effective apparatus for applying strips of film to large areas of ground surfaces.